Exploration into Potential Functionality of Hydroxylamine-Based Compounds and Development of Novel Synthetic Processes

Highly diverse organic reactions with hydroxylamine-based compounds have been developed during past ten decades or more and are now playing an important role in organic synthesis in a myriad of contexts. Nevertheless, we expect that there still remains useful and promising functionality for the compounds of this class. Hence, we have been making extensive efforts to disclose hidden potential of such compounds. In this report we will present some interesting and powerful organic transformations becoming available as the results of such our activities, which covers the following five novel processes or reactions: (1) silicon-tether strategy for controlling the regioselectivity and diastereoselectivity of intramolecular nitrone cycloadditions; (2) intramolecular Diels-Alder reactions employing hydroxamate tethers; (3) novel [2,3]-sigmatropic rearrangement for carbon-nitrogen bond formation; (4) dicobalt octacarbonyl-promoted rearrangement of 4-isoxazolines to acylaziridines; (5) novel ene-like cycloisomerization reaction of nitrile oxides with a tethered allyltrimethylsilyl group.